The Mother We Share
by r2roswell
Summary: Takes place not too long in the future. Alexis bonds with her step-mom and baby brother. This story came as a result of talking with a friend as we discussed what a great big sister Alexis would be one day.
1. Morning Wails

_In the dead of night_

_I'm the only one here_

_And I will cover you…_

_And the mother we share_

_Will never keep your proud head from falling_

_The way is long_

_but you can make it easy on me_

_And the mother we share_

_will never keep our cold hearts from calling…_

_Until the night falls_

_We're the only ones left_

_I bet you even know,_

_Where we could go_

_And when it all fucks up,_

_You put your head in my hands_

_It's a souvenir…_

_[-The Mother We Share, Chvrches]_

* * *

**1\. Morning Wails**

2:18 AM. Six week old Derrick Jameson Castle, Jamie, had been fed forty-five minutes ago. The loft had been peaceful for that time until once again the incessant wailing began. This was the part most adults didn't care for.

For Kate Beckett Castle it was a mixture. Sometimes she didn't mind it because she loved being a mother but there were times when she selfishly wished for a pre-baby life so she could get some descent sleep like before.

Beckett nudged her husband. "Your turn," she said to him.

"Kay," Castle said groggily, "In a minute."

"Castle," Beckett said as she continued to hear her son cry.

"I'm going, I'm going," Castle said as he still did not move from his place in bed.

All they both wanted was some sleep but with a baby that was all ready a month and a half it still wasn't possible. Beckett had hoped it would get easier but of course she had forgotten what having a baby was like. Nearly a year ago she and Castle had taken temporary custody of a three month old that still had constant crying fits. It was only now as Jamie continued his cries that Beckett remembered what it was like having Benny in their home. His constant crying had been a turn off for Beckett and she had told Castle that his plan of turning her into a baby person wasn't working.

It felt completely different now that they had a child of their own; Beckett actually finding the sound of Jamie's cries cute but it was still tiring as hell.

"Do you hear anything," Beckett asked as the crying stopped.

"I hear nothing," Castle said still groggy, "Go back to sleep."

"He stopped," Beckett said now fully alert.

"Good boy." Castle raised his head also, becoming aware, "Wait why did he stop? Is he supposed to do that?"

"You don't remember," asked Beckett, "I thought you were Superdad."

"Hey, I am totally Super Dad but the last time I did this was nearly twenty some years ago."

"I'm gonna go check on him," Beckett said getting out of the bed.

"Want me to come with," Castle asked.

"No, you have a book to write in the morning, get more sleep," Beckett said leaving the room.


	2. The Mother We Share

**2\. The Mother We Share**

Alexis smiled at the little guy on the changing table.

"There you go buddy," she said as she got him in a little blue onesie with dinosaurs. "All better."

She had changed his diaper and placed him in some fresh clothes.

She gently lifted him and cradled him in her arms. Jamie's tiny eyes followed his big sister.

"You know you're pretty great," Alexis said and then shrugged, "When you're not crying."

Rather than putting Jamie down in his crib and leaving the room, Alexis walked over to the rocker, not wanting to leave her brother just yet.

"I know there's a huge age gap between you and me but I promise you're going to love having me as a sister once you really get to know me. I've been an only child for a long time so it's nice to have someone new in the family. I'm really glad my dad and our mom had you."

Alexis took a moment to think about what she had said and then smiled to herself and smiled at her little brother.

"It's kind of complicated Jay but I'm going to tell you anyways: you see I do have my own mom. Like you were in Kate's belly, I was in someone else's baby. And she's great, I love my mom but she wasn't really there for me. She's kind of like… she's kind of like Aunt Lanie- she's around some of the time but not all the time and she spoils with presents like crazy. My mom wasn't really much of a mom. And I was okay with that but then you grow up and sometimes you wish you had a mom for all the difficult stuff.

Your mom though is a great mom and she loves you so much. She won't leave you the way my mom left me. And you know in a way I kind of think of her as my mom too." Alexis again smiled, "Kate was there for me when I grew up. She was there a lot of times when I was in high school and would spend time here at home and that was before she and dad got engaged.

My point is that you and I, we got lucky with Kate. You may not know Grandma Johanna but I'm sure she'll tell you about her some day and I actually think if our mom can do an amazing job before you were born, she'll continue to be an amazing mom to both of us."

Jamie let out a small yawn.

* * *

From the doorway Beckett could no longer hold back her tears as she had watched Alexis with her little brother. She quickly wiped her tears away with the back ends of her hands and made her way into the room.

"Hey you two," Beckett whispered as she went over to her two wonderful children

Alexis looked up and smiled. "Hey, I didn't mean for you to get up," Alexis said also in a whisper.

"It's okay. Actually when he stopped crying is when I started to worry."

"Sorry about that, I just figured you and dad would want your sleep."

"No don't be, thank you for getting him. You didn't have to do that, Alexis."

"I know. I like spending time with him though even if it's in the middle of the night. I changed his diaper and his clothes."

"You're an excellent big sister." Beckett looked down at her son and then at Alexis. "You know I love you right? Having your brother doesn't mean I don't love you any less."

Alexis nodded, "I know."

"And not just that but Alexis, I do see you as my daughter."

"You do?"

"Of course. You're my husband's daughter and you're my son's sister. We're family, Alexis. I know in the past we've had a kind of mentor-friend type of relationship but I'd like to think it's become more than that."

Alexis nodded. It had become more than that. Not too long after Kate had married her father, Alexis had begun giving goodbye kisses to Kate, changing their dynamic completely.

"So is it okay if I start calling you mom then? I know you're not trying to replace my other mom but I never see her enough and you've been there for me in ways that she hasn't. It's actually been nice over these years."

Beckett smiled, "Call me whatever you feel comfortable with."

Alexis smiled back and again Jamie yawned as he finally closed his eyes, finally tired and bored with the conversation.

"Guess we should put someone to bed," Beckett said to Jamie. Alexis gently handed her little brother over. "Come on Cosmo," Beckett said using Castle's nickname for their son, "Time for a little sleep before you wake me up again for another feeding."

The two of them stood, Alexis gently helping Beckett to her feet due to the tiny bundle in her arms. She then leaned in and placed a kiss on Jamie's forehead.

"Night buddy," said Alexis.

Beckett smiled at the little interaction as she walked over to the crib and gently got Jamie swaddled in a blanket. He was all ready asleep but Beckett ran her hand over his tiny body anyways. Only six weeks old and still Beckett felt like the luckiest woman in the world. She had never really imagined herself as a mother, not since her own mother had passed but now she couldn't imagine a role that was any greater, not since that first moment when she'd seen the positive sign on the first and second and third tests.

As much as she could stare at him for hours on end, Jamie would be up and crying in an hour or two so she needed to get what sleep there was.

Beckett guided Alexis out of the room and closed the door behind them.

"Thank you Alexis," said Beckett, "For looking after your brother."

Alexis smiled, "Anytime, 'night mom."

Beckett smiled back at the new moniker, "'Night sweetheart," she said as she watched her daughter make her way back down the hall to her room and as she made her way back downstairs.


	3. Our Son, Our Daughter

**3\. Epilogue- Our Son, Our Daughter**

Castle watched as his wife made her way back into the bedroom and waited until she was back at his side.

"How's Cosmo?" he asked.

"Perfectly safe," Beckett replied, "Alexis took care of him."

"She did? She got up, got him to stop crying and everything?"

Beckett nodded, "Changed his diaper, changed his clothes and then held him in her arms while she waited for him to fall back to sleep. You should have seen it Castle, it was beautiful. Safe to say our daughter loves her little brother."

"Well how could she not, everyone loves that little guy. Wait, did you just say 'our daughter?'"

Beckett looked over at her husband and smiled and then bit her lip nervously, "Too weird?"

Castle wrapped his arm around his wife as she settled into his chest, "Not weird at all. I'm glad she see's you as her mom. I mean biologically Meredith always will be but you've been there for Alexis in ways that Meredith never was. I probably haven't told you this but it's one of the many things I love about you, the fact that you've always had this bond with her. It's nice to see it grow."

"So you're okay with it, you're okay with her calling me 'mom'?"

"Honey I am more than okay with it," Castle said placing a kiss on his wife's forehead.

Beckett smiled as she closed her eyes as did Castle for the final remainder hours of sleep that they had left before Jamie woke them up again.

* * *

**~END~**


End file.
